ADA Accessible Routes and Paths of Travel: Widths, Slopes, Ramps

The Americans with Disabilities Act sets specific ADA accessible route requirements for any continuous, barrier-free path connecting arrival points to building entrances and connecting accessible elements within a site. Under the 2010 ADA Standards for Accessible Design, an accessible route must be at least 36 inches wide, have a firm and slip-resistant surface, run no steeper than a 1:20 slope, keep vertical changes under a quarter inch without treatment, and stay clear of protruding objects in the 27-to-80-inch zone above the floor.¹ The rules apply to new construction and, with some limits, to alterations of existing buildings.

Width, Passing Spaces, and Turns

The baseline clear width for an accessible route is 36 inches. That width can narrow to 32 inches at a single pinch point such as a doorway, but only for a maximum distance of 24 inches, and narrowed segments must be separated by stretches at least 48 inches long and 36 inches wide.² Treating 32 inches as the default width rather than a brief exception produces a route that fails compliance along its entire length.

Any accessible route narrower than 60 inches needs a passing space every 200 feet so two wheelchair users can get around each other.¹ Each passing space must be at least 60 inches by 60 inches. A T-shaped turning space works as an alternative: the overall footprint is still 60 by 60 inches, but formed by three intersecting segments, each extending at least 48 inches beyond the intersection.³ T-shapes often fit into floor plans where a full square won’t.

Where a route makes a 180-degree turn around an obstacle narrower than 48 inches, such as a column or partition, the clear width at the turn must be at least 48 inches and the approach must be at least 42 inches wide. A turn that provides 60 inches of clearance does not require the wider approach.² These are minimums for a power chair to complete the maneuver without backing up.

Surfaces Underfoot

Every inch of an accessible route must be firm, stable, and slip-resistant.¹ Firm means the surface resists deformation under a wheelchair. Stable means it stays in place when someone rolls across it; loose gravel and thick sand fail this test. Slip-resistant means adequate friction in both wet and dry conditions.

Openings in the Surface

Drainage grates, utility covers, and expansion joints cannot pass a sphere larger than half an inch in diameter.⁴ Where openings are elongated, such as the slats in a metal grate, the long dimension must run perpendicular to the direction of travel so narrow casters don’t drop into the gaps.

Carpet

Carpet is allowed on accessible routes if pile height stays at half an inch or less, measured to the backing or pad.⁵ The carpet must be firmly attached so it doesn’t shift under wheeled traffic. Exposed edges need trim along the full length, fastened down. Trim that creates a level change greater than a quarter inch must be beveled, and no carpet trim can exceed half an inch in height.

Slopes and Level Changes

The running slope of an accessible walking surface, measured in the direction of travel, cannot exceed 1:20, which works out to a 5% grade.⁶ Anything steeper is legally a ramp and must meet the more demanding ramp standards. Cross slope, the incline perpendicular to travel used for drainage, cannot exceed 1:48, roughly 2%. Even a small excess causes wheelchairs to drift sideways, forcing constant correction.

Vertical Level Changes

Small transitions between materials are governed by strict thresholds. A vertical change up to a quarter inch is allowed with no treatment. Between a quarter inch and half an inch, the edge must be beveled at a slope no steeper than 1:2. Anything greater than half an inch requires a ramp.⁴ These thresholds control transitions between tile and carpet, concrete and asphalt, or interior and exterior walkways.

Ramp Rules

Once a path exceeds a 1:20 running slope, ramp requirements apply. The maximum running slope for a ramp is 1:12, one inch of rise for every 12 inches of run, and cross slope still cannot exceed 1:48.¹ No single ramp run can rise more than 30 inches before hitting a level landing. Ramps can have any number of runs, but each one needs a landing at top and bottom.

Landings must be at least 60 inches long and at least as wide as the ramp itself. Where a ramp changes direction, the landing must be at least 60 by 60 inches.¹

Existing buildings get a narrow exception when space constraints make a 1:12 slope physically impossible. A slope between 1:10 and 1:8 is allowed only for a maximum rise of 3 inches, and a slope between 1:12 and 1:10 is allowed for a maximum rise of 6 inches.¹ Slopes steeper than 1:8 are prohibited under all circumstances.

Handrails on Ramps

Any ramp rising more than 6 inches needs handrails on both sides. Handrail height must be consistent at 34 to 38 inches along the run, and the gripping surface for circular cross-sections must be between 1¼ and 2 inches in diameter.⁷ Handrails must extend horizontally at least 12 inches beyond the top and bottom of the ramp run and then return to a wall, guard, or landing surface.¹ Gripping surfaces must be free of sharp or abrasive elements.

Doors Along the Route

An accessible route is only as good as the doors on it. The minimum clear opening width for a door is 32 inches, measured with the door open 90 degrees from the stop to the face of the door.⁸ If the doorway itself is deeper than 24 inches, as with thick walls or vestibules, that clear width increases to 36 inches.

Maneuvering clearance on both sides of a door depends on the direction of approach, whether the door swings toward or away from you, and whether it has a closer or latch. These clearances must be free of obstructions from the floor up to at least 80 inches, with no level changes beyond the threshold. Hardware must be operable with one hand, without tight grasping, pinching, or twisting, and must require no more than 5 pounds of force.⁸ Round doorknobs fail this test. Lever handles and push bars pass it.

Protruding Objects and Head Clearance

Accessibility standards extend up into the vertical space a person moves through. A white cane sweeps an arc close to the ground and reliably detects objects with a leading edge at or below 27 inches. Objects mounted between 27 and 80 inches above the floor fall outside cane range and become invisible hazards.⁹

For wall-mounted objects in that 27-to-80-inch zone, the maximum protrusion into the circulation path is 4 inches.¹ Fire extinguisher cabinets, sconces, and display cases are common offenders. An object can stick out further if it’s recessed into an alcove so nothing extends beyond 4 inches from the surrounding wall face.

Free-standing objects on posts or pylons follow a different rule. If the leading edge sits between 27 and 80 inches high, the object cannot overhang the post by more than 12 inches.⁹ Objects mounted below 27 inches or above 80 inches can protrude any amount, because low objects are within cane sweep and high objects clear head height.

Minimum vertical clearance along any accessible route is 80 inches.¹ Where clearance drops below that, such as under a staircase or a sloped ceiling, a detectable barrier must be installed within cane-detectable range to warn people before they walk into it.

Where Accessible Routes Must Exist

At least one accessible route must connect every site arrival point, including accessible parking spaces, passenger loading zones, and public transit stops, to the accessible building entrance it serves.² The route must be continuous, with no stairs, abrupt level changes, or gaps that force someone to backtrack.

On sites with multiple buildings, such as shopping centers, office parks, and campuses, accessible routes must link all accessible buildings, facilities, and elements to each other.² Outdoor amenities like benches, restrooms, and trash receptacles are included. A common failure is connecting parking to the front door but ignoring the paths between buildings or to outdoor gathering areas.

Curb Ramps

Where an accessible route crosses a curb, a curb ramp or level transition is required. Running slope of a curb ramp cannot exceed 1:12.⁷ Every curb ramp needs a level landing at the top at least 36 inches deep. Flared sides cannot exceed a 1:10 slope. In alteration projects without adequate landing space, flared sides must be provided at a maximum slope of 1:12.

Multi-Story Buildings

Multi-story buildings generally need an elevator or ramp to connect floors as part of the accessible route. Private buildings get a limited exception: if a building has fewer than three stories, or if each story is under 3,000 square feet, an accessible route between floors is not required.¹ The exception disappears entirely for shopping centers, healthcare providers’ professional offices, transit stations, and airport terminals; those buildings need vertical access regardless of size or number of stories.

Alterations and the 20% Path-of-Travel Rule

Renovating an area where a primary function takes place, such as a bank’s customer lobby, a restaurant’s dining room, or office work areas, triggers a duty to bring the accessible path of travel serving that area into compliance. Primary function areas do not include mechanical rooms, storage closets, employee break rooms, or corridors.¹⁰

The path-of-travel obligation covers the route itself plus the restrooms, telephones, and drinking fountains serving the altered area. The cost of these accessibility improvements is capped at 20% of the overall renovation cost. If full compliance would cost more than 20%, the path of travel must still be improved to the extent possible within that budget.¹⁰

When the budget runs short, the regulation sets a priority order for what to fix first:

An accessible entrance
An accessible route to the altered area
At least one accessible restroom for each sex, or a single unisex restroom
Accessible telephones
Accessible drinking fountains
Additional elements such as parking, storage, and alarms

An accessible entrance always comes before an accessible restroom under the 20% cap.¹⁰

Splitting a large renovation into smaller projects to stay under the trigger doesn’t work. If you alter a primary function area without addressing the path of travel and then do more work within the next three years, the government aggregates the cost of all alterations in that three-year window to determine whether the 20% threshold has been reached.¹⁰

Safe Harbor, Infeasibility, and Historic Properties

If a specific element in your building already complied with the 1991 ADA Standards when it was built or last altered, you don’t have to retrofit that element to the 2010 Standards until you next alter it. The safe harbor is element by element, not building-wide, and applies to each individual feature separately.¹¹ The same safe harbor extends to path-of-travel elements associated with an altered area. Once you do touch an element, the 2010 Standards apply in full.

Where full compliance during an alteration is physically impossible, the standards recognize technical infeasibility. It applies when existing structural conditions would require removing or altering a load-bearing member essential to the structural frame, or when other physical or site constraints prevent full compliance.¹² Technical infeasibility is not an exemption from compliance; you must still comply to the maximum extent that is technically feasible. The determination is scope-specific: constraints that justify partial compliance in a minor renovation may not survive a gut-level rebuild that has the reach to address them.

Qualified historic buildings follow the standard alteration requirements, with an additional exception when compliance would threaten or destroy the building’s historic significance. If the State Historic Preservation Officer or the Advisory Council on Historic Preservation makes that determination, alternative methods of access must be provided instead.¹³ Alternatives might include audio-visual presentations of inaccessible portions of a historic house museum or relocating programs to accessible locations within a historic government building. Physical access remains the priority; alternatives are a last resort.

Enforcement Exposure

The Department of Justice enforces these standards under Title III for public accommodations and commercial facilities. Civil penalties are adjusted annually for inflation. As of a 2014 adjustment, the maximum civil penalty was $75,000 for a first violation and $150,000 for subsequent violations, and those amounts have been revised upward multiple times through required annual inflation adjustments since then.¹⁴ Private individuals can also file lawsuits seeking injunctive relief, and in many jurisdictions prevailing plaintiffs recover attorney’s fees. The financial exposure from a single lawsuit frequently exceeds the cost of building the route correctly the first time.

1
ADA.gov. 2010 ADA Standards for Accessible Design
2
U.S. Access Board. Chapter 4: Accessible Routes
3
U.S. Access Board. Chapter 3: Clear Floor or Ground Space and Turning Space
4
U.S. Access Board. ADA Standards – Chapter 3: Building Blocks
5
U.S. Access Board. Chapter 3: Floor and Ground Surfaces
6
U.S. Access Board. ADA Standards Chapter 4 – Accessible Routes
7
U.S. Access Board. Chapter 4: Ramps and Curb Ramps
8
U.S. Access Board. Chapter 4: Entrances, Doors, and Gates
9
U.S. Access Board. Chapter 3: Protruding Objects
10
eCFR. 28 CFR 36.403 – Alterations: Path of Travel
11
ADA.gov (Archive). Fact Sheet: Highlights of the Final Rule to Amend the Department of Justice’s Regulation Implementing Title III of the ADA
12
U.S. Access Board. Chapter 2: Alterations and Additions
13
U.S. Access Board. ADA Accessibility Standards
14
ADA.gov. Civil Monetary Penalties Inflation Adjustment Under Title III